scholarly journals Quantum thermal transport and spin thermoelectrics in low-dimensional nano systems: application of nonequilibrium Green's function method

2015 ◽  
Vol 64 (18) ◽  
pp. 186302
Author(s):  
Chen Xiao-Bin ◽  
Duan Wen-Hui
Keyword(s):  
Thermal Transport ◽  
Function Method ◽  
Low Dimensional

scholarly journals Size-dependent phononic thermal transport in low-dimensional nanomaterials

2020 ◽  
Vol 860 ◽  
pp. 1-26 ◽  
Author(s):  
Zhongwei Zhang ◽  
Yulou Ouyang ◽  
Yuan Cheng ◽  
Jie Chen ◽  
Nianbei Li ◽  
...  
Keyword(s):  
Thermal Transport ◽  
Size Dependent ◽  
Low Dimensional

Thermal Transport in Nanostructured Solid-State Cooling Devices

2005 ◽  
Vol 127 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Deyu Li ◽  
Scott T. Huxtable ◽  
Alexis R. Abramson ◽  
Arun Majumdar
Keyword(s):  
Thermal Conductivity ◽  
Solid State ◽  
Nanostructured Materials ◽  
Thermal Transport ◽  
Experimental Studies ◽  
Phonon Transport ◽  
Peltier Effect ◽  
Cooling Devices ◽  
Low Dimensional ◽  
Solid State Cooling

Low-dimensional nanostructured materials are promising candidates for high efficiency solid-state cooling devices based on the Peltier effect. Thermal transport in these low-dimensional materials is a key factor for device performance since the thermoelectric figure of merit is inversely proportional to thermal conductivity. Therefore, understanding thermal transport in nanostructured materials is crucial for engineering high performance devices. Thermal transport in semiconductors is dominated by lattice vibrations called phonons, and phonon transport is often markedly different in nanostructures than it is in bulk materials for a number of reasons. First, as the size of a structure decreases, its surface area to volume ratio increases, thereby increasing the importance of boundaries and interfaces. Additionally, at the nanoscale the characteristic length of the structure approaches the phonon wavelength, and other interesting phenomena such as dispersion relation modification and quantum confinement may arise and further alter the thermal transport. In this paper we discuss phonon transport in semiconductor superlattices and nanowires with regards to applications in solid-state cooling devices. Systematic studies on periodic multilayers called superlattices disclose the relative importance of acoustic impedance mismatch, alloy scattering, and crystalline imperfections at the interfaces. Thermal conductivity measurements of mono-crystalline silicon nanowires of different diameters reveal the strong effects of phonon-boundary scattering. Experimental results for Si/SiGe superlattice nanowires indicate that different phonon scattering mechanisms may disrupt phonon transport at different frequencies. These experimental studies provide insight regarding the dominant mechanisms for phonon transport in nanostructures. Finally, we also briefly discuss Peltier coolers made from nanostructured materials that have shown promising cooling performance.

Thermal transport and spin-dependent Seebeck effect in parallel step-like zigzag graphene nanoribbon junctions

2020 ◽  
Vol 22 (34) ◽  
pp. 19100-19107
Author(s):  
Xingyi Tan ◽  
Lili Liu ◽  
Gui-Fang Du ◽  
Hua-Hua Fu
Keyword(s):  
Density Functional Theory ◽  
Molecular Dynamic ◽  
Thermal Transport ◽  
Density Functional ◽  
Function Method ◽  
Graphene Nanoribbon ◽  
Seebeck Effect ◽  
Functional Theory ◽  
Spin Dependent Transport ◽  
Dependent Transport

By using nonequilibrium molecular dynamic and density functional theory combined with nonequilibrium Green's function method, thermal transport and spin-dependent transport through a series of parallel step-like graphene nanoribbon (GNR) junctions are investigated.

Electronic and thermal transport in hot carrier solar cells with low-dimensional contacts

2008 ◽  
Vol 39 (3-4) ◽  
pp. 656-659 ◽  
Author(s):  
M.F. O’Dwyer ◽  
T.E. Humphrey ◽  
R.A. Lewis ◽  
C. Zhang
Keyword(s):  
Solar Cells ◽  
Thermal Transport ◽  
Hot Carrier ◽  
Low Dimensional

Thermal Conductivity of α-Tetragonal Boron Nanoribbons

2009 ◽  
Author(s):  
Scott W. Waltermire ◽  
Juekuan Yang ◽  
Deyu Li ◽  
Terry T. Xu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Transport ◽  
Room Temperature ◽  
High Hardness ◽  
Mean Free Path ◽  
Good Oxidation Resistance ◽  
Elemental Boron ◽  
Past Half Century ◽  
Materials Research ◽  
Low Dimensional

Elemental boron has many interesting properties, such as high melting point, low density, high hardness, high Young’s modulus, good oxidation resistance, resulting from its complex crystalline structure from its electron-deficient nature. Boron forms complex crystalline structures according to the various arrangements of B12 icosahedra in the lattice, such as α (B12)- and β (B105)-rhombohedral and α (B50)- and β (B196)-tetragonal boron polymorphs, among others. Even though considerable materials research has been conducted over the past half century on boron and boron-based compounds, investigating their unique structures and corresponding properties, our understanding of this complex class of materials is still poor, compared to some other well-studied materials with much simpler structures such as silicon. Thermal transport studies through bulk boron have been performed mainly on β-rhombohedral and amorphous boron, because of the difficulty to grow high quality bulk α-rhombohedral boron samples [1–3]. Some efforts have been made to measure B12As2, B12P2, AlB12 samples that have an α-rhombohedral form [2,3]. There is almost no information available on α-tetragonal boron. However, Slack predicted the thermal conductivity of α-boron should be ∼200 W/m-K at room temperature, which is 1/2 that of copper. Large phonon mean free path has been predicted for α-boron (from ∼200 nm at room temperature to 6 nm at the Debye temperature), which could lead to interesting thermal transport properties for low dimensional boron structures.

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